spatta



8, 1936; a. SPATTA AXLE CASING AND METHOD OF MAKING THE SAIE Original Filed Dec. 26, 1929 2 Sheets-Sheet 1 Sept. 8, 1936. I G, 5PM Re. 20,103

AXLE CASING AND METHOD OF MAKING THE Sm Original Filed Dec. 26, 1929 2 Sheets-Sheet 2 Ma ts, was

UNITED sTArssi PATENT orrice a'xu: cssmo sun mrrnon or llama m am GeorgeSpatta,

s sr Buchanan, Mich, to Clark Equipment Company, Buehamn, Iieh" Michigan aeorporation of Original no. 1,020,353, dated m 1:, 1m, 7

Serial No. 6587. December 26, 1929. Applieation'forrehsnelanell,

Myinventionrelatestoaxlecasingsandthe methodofmakingthesame.

Itisoldtoconstructarearaxlecasingor housingfromapieeeoftubingsllypreaentinvention proceeds, however. upon the concept of I such a process of construction as'will produce a satisfactory product for the purpose intended 'and in which process the steps are peculiarly adapted for machine operation.

Those familiar with present methods of mass production recognise the desirability of reducing any manufacturing process to such operations as involve a=low or minimum labor cost in the final cost price. This requires a carefully '1 engineered process and plant. entailing a minimum of hand operations and the maximum cm ployment of The use of machinery involves skilled operators and careful supervision of all operations. Thus, apart of the cost re-, duction which is gained by elimination of hand operationsby unskilled operators is lost by the employment of machinery under skilled opera! tors. which are necessarily higher priced. However,- it,is the general experience that a higher paid machine operator can. under properly engineered plant and process conditions. perform far more work than lower priced labor with hand operations.

I have aimed; in -the presentlinventionrto provide a process, a plant. and a product which will permit of the manufacture ofa strong' light and highly satisfactory l'Q8l axle 1mm;

orcasingata highrateof productionand at.

loweost. In brief, the present application is directed to .theproductand the process ofmakingthesame.

The plant, including a relatively large numbers of machines. some of which are new and some of which are old. iscovered' by a series of copending applications, towhich reference will be made hereafter more in detail for an explanatien of any peculiarities in the individual steps, 0: the manner of their performance.

' 45 to the' present invention I produce 1.

blank which has a wall thickness substantially thesameas joframe- Theendsofthistubeareshnmk-to o of'thearms. Such increaseofthewallthickness'oi'tisearmsofthe final of the banms, Serial no.

' :1 china. (01. sa-is'sn sndtheenlargedseatsforthewheel aretobeformed'."rheiiangeandbrakedrum.

andseatsforthebearingsrequireextrametal to be secured for their formation andthis mm is gathered by endwise swaging. This operationof endwise swaging-and expanding'is more readily performed in one heat. when the walls of the arms are relatively thick. Hence. while there apparently is slightly more metal in the armsthanisforstrengtl theresultan't product is secured with fewer operations and hence at lower cost. Y

Now, in order to acquaint those skilled in the art with the manner of constructing the housingof my invention according to the process, of my invention, 1 shall describe, in connection with the accompanying drawings' a typical manner of producing the housing according to the present invention.

In the drawings: Figure 1 isa side eievational view of the tubular blank.

Figure2isanendviewoftheila-me. v Figure 3 is'asideelevationalviewof theblank with. the initial perforations formed ln-one wall I'iguieiisasectbntakenonthelinei-lof rigurea. v

Figure 5 is aside elevational view of the blank aftertheslottingeperation.

7 is aside elevational view of the blank after the first-operation of shrinking the arms on each side of the slottedcentral portion.

Figure 8 is an end elevational view of the same. I'ixure 9 is a side elevational view of the blank after the second shrinking operation.

Plsureloisanendelevationalvlewofthe elevational view at the operation.

Figure 1s a a sideelevational view of are blank after the slotted central portion is spread out for the insertion of a forming die.

I'isure iiisasection'ofthesamatakenon line ll-' 0! 81118 13. e

Figure 15 is a sideelevational view of the blank after the forming operation of the banjo frame I portion.

Figure loisa cross taken on theiine.

- -10 or l'isure is.

"l8ure-1'lisasideelevationslviewoftheblank is'iisectionontheiinel-Cof' Figure 12 an end elevational view of the v afterthe throating, or throat-forming operation. a suitable tubular blank as shown in Figs. 1

Figure 19 is a cross sectional view taken on the line ll-lt of Figure 17.

Figure 19 is a side elevational view of the blank alter flattening and machining out the flanges of the banjo frame. v

Figure 20 is a cross sectional view taken on the line 29-29 of Figure 19.

Figure 21 is a side elevational view with a part of one arm broken away after the first swaging operation on the ends of the blank.

Flgure22 is a sectional view taken on the line 22-22 of Figure 21.

Figure 23 is a side elevational view of the blank after the second swaging operation on the ends of the arms.

Figure 24 is a section taken on the line 2l-2l of Figure 23.

Figure 25 is a side elevational view of the blank after the third swagingpperation on the ends of the arms for producing the brake drum attaching fiange and for forming the bearing seats.

Figure 26 is a section taken along the line 26-29 of Figure 25.

Figure 27 is a side elevational view of the housing, showing the spring-seat welded onto the axle arms.

Figure 28 is a sectional view taken on the line 28-28 of Figure 27.

In the production of the casing herein illustratedthe first step is the production of the tubular blank I, shown in Figs. 1. and 2. The character of the finished casing to be produced controls the character of' the blank which isto be produced. Hence the production of the blank must be controlled to suit the form, size, weight, etc., of the final casing to meet the requirements of the customer.

In one typical example I produce a tubular blank 55 inches long, 4 /4" outside diameter with a wall thickness. The tube may be seamless or may be welded and it should have a certain degree of hardness approximating a Brinell test of 150 (between 140 and 150) as will be apparent from the following description.

The blank must undergo considerable working and particularly the shrinkage of the arms as shown in Figs. '1 to 12. which compacts and hardens the metal. and which is performed cold, requires a relatively closely controlled quality and type of blank.

Theblankimaybeproducedbycuttingofl a length of seamless or welded tubing which is suitably drawn orformed, as now known to the prior art. or I may form, the relatively short length of tubing which is required by deep drawing. or by extrusion.

Thewallthicknessoftheblank l hasacertain relationtothefinished casing, which I shall now explain.

- Consider the finished casing shown in Fig. 27; the section on the line A-B represents approximately the critical section and this corresponds to the critical section shown on line A-B ofFlg. 5. Thatistosay, the maximum spread ofmetalisonlinea-B ofFig. 27 sndthe metal mustbepreuntintheblankonthe line ABotFig.5inorderto produceully the finished article. If there is sufilcient metal on the section A-IB of Fig. to produce the required thickness of wall on the line A-IB of Fig. 2'! then there is ample metal for all other parts or the casing.

The first step is, therefore, the production of and 2.

Thenext main step is the step of slotting the tube as shown in Figs. 5 and 6. In order to accomplish this slotting the tube blank I is first put upon a horn die and an external punchpunches the perforation 2. The .perforated blank 9 is then slipped over a horn punch and the pressure pin projects through the perforation 2 to drive the horn punch through the bottom wall of the tube to form the slot 4. The tube is then turned 180 degrees on the horn punch and the pressure pin again actuates the punch to produce the slot 9 which is accurately in register with the slot 4. This leaves the slotted blank 9.

It will be observed that the slots are slightly wider at the center than at the ends. .The shape of the slots is designed to give a proper distribution of the metal so that the edges of the slots 4 and 5 will, under the treatment hereinafter described, define circular openings for the banjo frame, leaving substantially uniform width of flange at the banjo frame opening. I The blank 5 is then gripped at the central part and ring dies for shrinking the ends of the tube are then passed over the'ends oi the tube in a first shrinking operation, leaving the piece in the form shown in Figs. 7 and 8. This constitutes the blank I. The blank has now assumed three distinct parts, namely, the central portion 9, from which the major part of the banjo frame is later, constructed, the arms 9-9 of reduced diameter, and the tapered intermediate or throat portions ill-l9. which form the junction between central portion 9 and the arms 9-9.

The central portion 9 is of the original diameter of the blank I., The ring dies, which are pressed towards each other by hydraulic pressure as will be disclosed more fully in co-pending application Case 15, have tapered forward ends which form the intermediate or throat portions Ill.

The shrinkage of the arms 9-9 to their final diameter is accomplished in three stages. The first stage is shown in Figs. 7 and 8. The second stage is shown in Figs. 9 and and the third stage is shown in Figs. 11 and 12. The

piece I is longer than the blank I or the pieces 9 01:9, which are of the same length as the blank I, and this increase in length is produced by the first arm shrinking operation of the dies aforesaid. The piece l2 which results from the second arm shrinking operation leaves the central portion 9 substantially as it was in Fig. 7.

the arms have been reduced in diameter andincreased in length, as shown in l9-i9 in Fig. 9 and the throat, or joining portions ll-il have likewise been increased in length.

The third arm shrinking operation produces the piece I shown in Figs. 11 and 12. In this case the central portion 9 remains the same. the arms l9 -|9 have now been brought to their final diameter and again. increased in length, while the throat portions lI-il are likewise v increased in length.

The piece II is then removed from the shrinking clutch andthe central portion 9 issubiectedtoaspreadingactionbythrustinga cylindrical member through the slots 4 and I. The forward end of the cylindrical member is tapered so as.to enter the slots readily and the cylindrical parts lying outside of the slots 4 and larespreadoutsubstantiallyfiat atthe center which heats one end of the arm, or if desired, I

both ends may be heated simultaneously, and therefrom the ends of the arms it are forged in a series of operations.

The arm ll which is to be forged is gripped in a particular position which is gauged from the banjo frame 25 and then, by endwise forging. the walls of the arm it are thickened as shown in Fig. 22.

Both arms are thus treated, thereby producing the relatively shorter piece 26, shown in Figs. 21 and 22, with the increased thickness of metal secured at the ends of the arms by gathering the same inwardly. This is plainly shown at 21 in Fig. 22. The dotted line showing in Fig. 22 illustrates the original length of the arm I and the increased thickness secured is from the metal which is gathered from the dotted portion.

The piece II is then transferred, while still hot, to the next set of forming dies where the arm I is further shortened and more metal gathered, as shown in section in Fig. 24. The metal which is gathered from the dotted line portion is partially thrown outwardly to form the flange ll as shown in Fig 24.

The piece 22, shown in-Figs. 23 and 24 is immediately transferred to'the next set of dies where the end of the arm I6 is completed by the flnal forging operation to shape the metal as shown in section in Fig. 26. Further metal is gathered, as indicated from the dotted line outline of Fig. 26 and this metal is thrown, with the other gathered metal into the full line section shown in Fig. 26, the flange 40 being increased in diameter and reduced in thickness and an internal seat 42 is formed for housing the wheel bearings.

The seat 42 for the bearings and the flange 40, for attaching the brake drum or the like, are

- later flnished by machining. The wall thickness at and adjacent the seat for the wheel bearings is slightly in excess of the thickness of the arms. This is advisable to provide suflicient metal for finishing the bearings seat, theflange 4' and the end face of the arm.

The piece 4!, as shown in Figs. 25 and 26 is substantially complete so far as forging is concerned. The outer face of the flanges 21-21 are adapted to be flnished in parallel planes for the bolting of a differential frame and a cover-plate upon opposite sides of 'the housing.

'The flanges 21-21 may be subjected to a flattening treatment which consists in lay the flange flat upon an anvil or other flat supporting surface and hammering the inside of the flange flat against the anvil. as by means of an airhammer or the like, which reaches inside of the banjo frame and strikes the inner surface of the flange 21 to be straightened. This operation is performed upon each flange 21 prior to machining of the outer surfaces.

Also, if desired, reinforcing rings made of flat plate stock may be welded to th 1 inside surfaces of the flanges 2121 to increase the stock which may be engaged by the tap screws which hold the cover-plate and the diflerential frame in place upon the banjo frame. Such reinforcing rings upon the .Liside of the flanges 21 are preferably applied in segment and hot-welded to the said flanges 21-21 prior to machining of the outer surface of the flanges. The flanges are then drilled and tapped.

The casing or housing is provided with spring seats "-44 which are formed of thin plate stock, drawn to shape. The spring seat II is formed of a flat top or platform portion 45 which is adapted to be placed horizontally on the top side of the casing arm, in such position as to register with the rear spring of the vehicle.

The platform 45 has integral depending walls "-46 terminating in cylindrical saddle portions 41-41 which saddle portions have their edges welded as by electric arc welding to the adjacent surface of the rear axle housing arm i6.

Preferably in the commercial manufacture of the housings these spring seats are located by means of jig fixtures upon the housing arms l6l6 and are tacked to the housing arms i8-i6 by hand applied are or gas weld to hold the spring seats properly in place upon the arms i6i6 .and thereupon the housing, with the spring seats tacked thereupon is placed in a suitable flxture and the four cylindrical'edges are welded simultaneously to the arms iB-il in an electric welding machine.

The welding of the spring seats is performed preferably after the machining-of the surfaces of the banjo frame and the ends of them,

so that the location of the spring seats is accurately disposed with respect to the flnished surfacesof the housing. However, this is not essential, as it is within the scope of my invention to weld the spring seat to the housing prior of the finishing of the surfaces to be machined, or any part of them.

It will be observed that the finished housing or casing is light and strong, the critical section on line A-.-B of Fig. 27 contains the original metal of the tube on substantially line A-B of Fig. 5. The metal of the original blank or tube I is sufficient to provide the critical section,

without appreciable diminution or weakening and the metal of the casing throughout has been worked and compacted. The result is a light, strong casing. costing less to produce than any casing of the same strength now on the market. For its weight the present axle casing has a strength far in excess of anything now found on the market. This is highly advantageous in that it reduces the unsprung weight of the rear axle constructions Idonotintendtobelimitedtotheprecise order of the steps heretofore described nor to the exact mode ofprocedure herein related, as itwillbeapparenttothoseskilledintheart that certain deviations therefrom are permissible within the teaching of my invention.

The forging steps shown in Figs. 21 to 26 are disclosed and claimed in detail in my co-pending application Case 22. The flattening of the flange oi the banjo frame is disclosed and claimed in detail'ln my .co-pending Case 20.

The step of welding the spring-seat to the casing is disclosed and claimed in detail in my co-pending Case 23.

I claim:

1. The process of forming a banjo frame axle housing which comprises; producing a tubular blank of substantially uniform diameter and 'eterwhichisapproximatelyequaltotbcperilm, eter of the-opening of the banjo frame open ing,shrinking the diameter of thearmstosubstantially the desired depth of banjo frame, thereby leaving tapered throat portions between the slotted part and the arms, spreading out flat in atransverse direction the cylindrical wallsatthe centralpartof theslottostretch the edges of the metal deflning the opening; and simultaneously spreading the banjo frame opening, throwing out the metal of the tube on each side of the slot into a transverse cylindrical shape on each side of the opening and folding tbemargininwardly toformabanjoframe which is rectangular in cross-section and of a -2.-The process of forming a banjo frame axle housing which comprises; producing-a tube of substantially imiform cross-section throughout andhaving a wall thickness and cross-sectional perimeter great enough to form the throat of the banjo frame, slotting the-tube to deflne a transverse banjo frame opening of greater widthatthecenterthanattheendaahrinking the diameter of the arms to substantially thedesired depth of the banjo frame when flnished,

forming tapered throat portions between the slotted portionand the arms, folding out substantially flat the centrai'part of the metal on each side of the slot and moving said flattened portions outwardly to increase the transverse opening, throwim outwardLv the central part of the metal oneachsideofthe'slottoformthe same into transverse cylindrical shape, folding in the end of under the I 3.Theprocessoiconstructingahollowbanio frame-axle housing froma prises: slotting the central bearing seat upon the inside.

Libemethodofformingatubularbanjo frame axle housing from a tubular blank which comprises slotting the central part of the inbularblanktoformacrosswisebanjoframeopening, increasing said opening by flattening "crosswise the central part of the slotted walls, forming into cylindrical shape the slotted partsof the blank and folding the margins inwardly to define flangeaupsettingthe end ofeach of'the arms to gather metal and forming said metal 'thicknessof the walls intoaflangeandexpandimtbeend-ofeachof thearms undertbe ansctopruvideabearing" 5. Themethodofinakingabaujoframawhlch comprises forming a centrally slotted tubular blank, shrinking-the diameter of the end portions on each side of the slotted portion to deflne arm's ofgreaterthlcknestbanthethicknessofthe original blank, opening out substantially flat the slotted portion to permit the insertion of an expanding die, expanding the central part ofthe slotted-portion and'folding over the margins to form parallelinturned peripheral flangestodeflne abanjoframaupsettingtheendsofthearms to gather stock for forming flangeslthen throwing the gathered metal out into flanges on the ends of the arms.

6. Themethodofformingabanjoframe axle housing which comprises,-producing atubular blank slotted at the central portion and having a substantially uniform wall thickness throughout, shrinking the arms on each side to increase the thicknessof thewallsofge of spreading out substantially .flat the arcuate walls at the central part of the slottedportion to admit a forming die, forming the central slotted part into a transverse cylinder with inturned flanges, and naming integral flanges on the ends of the arms by endwise forging.

I. As a new article of manufacture-a banjotype axle housing formed from a tubular blank central part,-

thickened, solid,integral flanges, said flanges beingformedbyupsettingthemetalof saidhousingendstoathicknessgreaterthanthatofthe remainder of said ends.

8. Inc method of forming banjo-type axle .housingathestepswhichccnsistin'forminga tubular blank. into a homing havingha central banjo frame portion and having oppositely extendingendsoftubularcrosssectionandupset tingthemetalattheextremityofsaidends'to provide'thickened, solid integral; annular flanges at each extremity of the 9.In a method of forming'banjo-type axle housings trom tubular blanks. thesteps which 'ingtherebetweenabanjo-shapeddifl'erentialcasing, clamping one tubular end of .such housing and forcing a suitably shaped heading the interior of saidflends and upsetting 11. A rearaxlehousing oppositely extending tubular arm portions having integral expandedthroat portionsattheirinnerfends con- Jointly defining a circular banjo frame, and upset inner ends to deflneagear'casing having parallel ing of the type having a central differential casing and tubular oppositely extending arm portions, the outer extremities of said arm portions terminating in thickened radial flanges havi radially enlarged and thickenedbearing seat portions at their inner faces joining said flanges to said arm portions.

14. As an article of manufacture. an axle housing of the type having a central differential casing and tubular oppositely extending arm portions, the outer extremities of said arm portions having radially expanded bearing seat portions of a wall thickness greater than that of said am portions and terminating in thickened radial 15. In a method of forming axle housings, the steps which consist in forming a hanichtype axle housing having ppositely extending tubular ends, clamping one tubular end of said housing in a die and forcing a suitably shaped heading tool into the interior of said end to form a preliminary upset, placing said end in a second clamping die and forcing a second heading tool into the interior thereof to form a flare at the extremity of said end and to shape said flrst flare into an intermediate shoulder. and placing said end in a third clamping die and forcing a third heading tool thereinto to shape said flare into an annular flange.

16. In a method of forming steps which consist in forming a banjo-type axle housing having oppositely extending tubular ends, clamping one tubular end of said housing in a die and forcing a suitably shaped heading tool into the interior of said end to form a preliminary upset, placing said end in a second clamping die and forcing a second heading tool into the interior thereof to form a flare at the extremity of said end and to shape said flrst flare into a thickener intermediate shoulder; and placing said end in a third clamping die and forcing a third heading tool thereinto to shape said flare into an. annular flange.

1'!. In a method of forming axle housings. the

axle housings, the

steps which consist in forming a banjotype axle housing having oppositely extendingtubular ends, clamping one tubular end of said housing in a die and forcing a suitably shapai heading tool into the interior of said end to form a preliminary upset, placing said end in a second clamping die and forcing a second heading tool into the interior thereof to form a flare at the extremity of said end and to shape said first flare into a thickened intermediate shoulder, and placing said end in a third clamping die and forcing a third heading tool thereinto to shape said flare liminary upset into a shoulder and to form a flare at the extremity of said tubular end, and clamping said tubular end ina third die and forcing a third heading tool thereinto to form said flare into a thickened annular flange, the plane of which is perpendicular to the axis of said tubular end.

19. As a new-article of manufacture, a banjotype axle housing formed at its ends with thickened, solid, integral flanges, said flanges being formed by upsetting the metal of said housing ends to a thickness greater than that of the remainder of said ends.

20. In a method of forming banjo-type +axie housings, the'steps which consist in forming a housing having oppositely extending ends of tubular cross section and upsetting the metal at the extremity of said ends to provide thickened, solid. integral, annular flanges at each extremity of the housing.

21. In a method of forming banjo-type axle housing, the steps which consist in forming a housing having oppositely extending ends of tubular cross section, clamping one tubular end of such housing in a die and forcing a suitably shaped heading tool into the interior of said end and upsetting. the metal thereof to form an integral annular thickened flange on said end.

. GEORGE SPA'I'IA. 

